ACTUAL LAB PROCEDURE Exercise 9A Transpiration In this lab, you will measure transpiration under various laboratory conditions using a potometer. Four suggested plant species are Coleus, Oleander, Zebrina, and two week old bean seedlings. Materials omL pipette, plant cutting, ring stand, clamps, clear plastic tubing, petroleum jelly, fan, lamp, spray bottle, and plastic bag. Procedures 1.Place the tip of a 0.1 mL pipette into a 16 -inch piece of clear plastic tubing. 2.Submerge the tubing and the pipette in a shallow tray of water. Draw water through the tubing until allthe air bubbles are eliminated. 3.Remove any buds from the plant. 4.Remove one (1), which is close in size/shape to the other leaves on your plant. This is a representation of all leaves on your and you will calculate the surface area of this leaf. 5.Carefully cut your plant stem under water. This step is very important, because no air bubbles must be introduced into the xylem. 6.While your plant and tubing are submerged, insert the freshly cut stem into the open end of the tubing. 7.Your potometer should look like: 8.If necessary use petroleum jelly to make an airtight seal surrounding the stem afterit has been inserted into the tube. Do not put petroleum jelly on the end of the stem.9.Let the potometer equilibrate for 10 minutes before recording the time zero reading. 10.Expose the plant in the tubing to the following treatments a). Room conditions b). Floodlight (bright light) c). Fan (place at least 1 meter from the plant, on low speed, creating a gentle breeze) d). Mist (mist leaves with water and cover with a transparent upside down/inverted fish aquarium) 11.Read the level of water in the pipette at the beginning of the experiment (t=0) and record data in your data table.